Former Oregon neurosurgeon Vishal James Makker surrendered his medical license this week following a state investigation into accusations that he performed unnecessary spinal fusion surgeries.

Between 2008 and 2009 Makker performed nearly 10 times more multiple spinal-fusion procedures than the average surgeon, according to a Wall Street Journal report.

Makker denied any wrongdoing, but surrendered his Oregon medical license, according to a report from the state medical board, which characterized the surgeon's conduct as "unprofessional or dishonorable."